You can use sp_helptext command to view the definition. It simply does
Displays the definition of a user-defined rule, default, unencrypted Transact-SQL stored procedure, user-defined Transact-SQL function, trigger, computed column, CHECK constraint, view, or system object such as a system stored procedure.
E.g;
EXEC sp_helptext 'StoredProcedureName'
EDIT:
If your databases
or server
are different then you can do it by specifying them as well
EXEC [ServerName].[DatabaseName].dbo.sp_helptext 'storedProcedureName'